Electrophotographic and structural studies on novel photoconductive polyimide films

Abstract

Novel photoconductive polyimides have been developed, whose monomer units are composed of a series of thiophenylene moieties, -C6H4S-, and imide groups. The most photosensitive polyimide shows an excellent photosensitivity of less than 1.0 μJ/cm2 in the visible light region, 400–570 nm. These photosensitive polyimide films are prepared by polymerizing the cast prepolymer films and annealing at the melting points of the polyimides. In this process their photosensitivities remarkably increase with the increase of crystallinity. From the structural studies by ultraviolet visible absorption, x-ray diffraction, infrared absorption, and x-ray photoelectron spectroscopy measurements, it is proposed that the coplanary conformation takes place in the crystallizing. The overlapped π orbitals, perpendicular to the polymer chains, lead to the more expanded conjugate system.

Synthesis and photoconductive characteristics of biphenylporphyrin‐containing poly(amic acid)s and polyimides

“…The photoreceptors and the photoinduced‐discharging processes were effectively used to characterize the photoconductive properties of these CGL materials (Fig 8). 16 In this work, the photoreceptors containing the CGLs prepared with the above polymers were charged with an initial surface potential ( V 0 (V)). The charge loss rate in the dark is described as dark decay ( R D (V s −1 )).…”

“…Based on the fact that the intrinsic photoconduction depends greatly on the aggregation of chromophores9 and the relatively limited aggregation of BPP units in HPIs, it was inferred that the intrinsic process contributed little to photoconduction in these polymers. The photoconduction of these HPIs was mainly generated from the extrinsic CTC process 16, 21. Although CTCs could also be formed between the diphenyl ether (DPE) units and imide units (DPE–imide, in addition to BPP–imide CTCs), in this case charge carriers could not be generated from such CTCs because their excitation energies were larger than the energy of the visible light source used 9, 22.…”

“…The PR was dried at 60 °C for 4 h before subjecting to photoconduction measurements. The photoconductivity was measured by using a photoinduced‐discharge (PID) process16 on a GDT‐II device, in which a corona charger was used. White light (100 lx), generated by a 5.0 W halogen lamp, was used as the photoexcitation source.…”

Photoconductive studies on Langmuir-Blodgett multilayers of a copolyimide containing phthalocyanine and carbazole

“…[1][2][3][4][5][6] However, Kapton is weekly of 0.4 nm have been successfully prepared using photoconductive. It was reported by Freilich 5 that a ''Precursor Method'' reported by Kakimoto and the addition of electron donors to Kapton polyimhis co-workers.…”

Photoconductivity of Aliphatic Polyimide.

“…[12] Also, the synthesis of new polyimides with various functional groups which show high photosensitivity, was carried. [13][14][15] In recent years, the polyimides prepared from alicyclic diamines are attracting much interests because they have good optical spectroscopic and dielectric properties as well as good thermal stability. [16][17][18] One of the reasons for their high performance is due to the elimination of charge transfer, while the charge transfer state of aromatic polyimides is formed between the aromatic diamines as electron donors and the aromatic dianhydrides as electron acceptors both intra-and…”